A fund that resets to L times an index every day grows, in the typical case, at about
r + L·(μ − r) − fee − L²·σ²/2. Put in your guesses and see whether the leverage pays.
3x trails the index in the typical case.
Orange: typical yearly growth at each leverage with your inputs. Dashed: the index. Past the peak, more leverage means less growth.
curl 'https://lev.wickkit.cc/?mu=10&vol=22&r=4&L=3' curl 'https://lev.wickkit.cc/api?mu=8&vol=16&L=2' # JSON (rates come back as decimals)
Assumes steady volatility and lognormal daily moves. Real volatility spikes when prices fall, which hurts leverage more than this says. Swap costs run a little above the cash rate. μ is the input nobody knows. Not advice. The derivation and a simulation are in The Break-Even Line for 3x.